Shareholders' Equity - Summary of Stock Option Activity (Detail)	9 Months Ended
	Sep. 30, 2016 USD ($) $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Number of Shares, Beginning Balance | shares	1,778,697
Granted, Number of Shares | shares	307,700
Exercised, Number of Shares | shares	(273,320)
Forfeited, Number of Shares | shares	(380,472)
Expired, Number of Shares | shares	(51,367)
Number of Shares, Ending Balance | shares	1,381,238
Vested and expected to vest, Number of Shares, Ending Balance | shares	1,305,619
Exercisable, Number of Shares, Ending Balance | shares	773,084
Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 4.43
Granted, Weighted Average Exercise Price | $ / shares	5.48
Exercised, Weighted Average Exercise Price | $ / shares	3.19
Forfeited, Weighted Average Exercise Price | $ / shares	5.31
Expired, Weighted Average Exercise Price | $ / shares	6.13
Weighted Average Exercise Price, Ending Balance | $ / shares	4.61
Vested and expected to vest, Weighted Average Exercise Price, Ending Balance | $ / shares	4.55
Exercisable, Weighted Average Exercise Price, Ending Balance | $ / shares	$ 4.02
Weighted Average Remaining Contractual Life (in years)	7 years 3 months 22 days
Vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	7 years 2 months 16 days
Exercisable, Weighted Average Remaining Contractual Life (in years)	6 years 2 months 27 days
Aggregate Intrinsic Value | $	$ 1,176,876
Vested and expected to vest, Aggregate Intrinsic Value | $	1,165,259
Exercisable, Aggregate Intrinsic Value | $	$ 948,542